org.mmtk.vm

Class Collection

java.lang.Object

org.mmtk.vm.Collection

Direct Known Subclasses:

Collection

public abstract class Collection
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static int	EXTERNAL_GC_TRIGGER Externally triggered garbage collection (eg call to System.gc())
static int	INTERNAL_GC_TRIGGER Internally triggered garbage collection.
static int	INTERNAL_PHASE_GC_TRIGGER Concurrent collection phase trigger.
static int	RESOURCE_GC_TRIGGER Resource triggered garbage collection.
static int	TRIGGER_REASONS The number of garbage collection trigger reasons.
protected static String[]	triggerReasons Short descriptions of the garbage collection trigger reasons.
static int	UNKNOWN_GC_TRIGGER An unknown GC trigger reason.

Constructor Summary

Constructors

Constructor and Description
Collection()

Method Summary

Modifier and Type	Method and Description
abstract void	blockForGC() Block for the garbage collector.
abstract int	getActiveThreads()
abstract int	getDefaultThreads()
abstract void	outOfMemory() Fail with an out of memory error.
abstract void	prepareMutator(MutatorContext m) Prepare a mutator for collection.
abstract void	requestMutatorFlush() Request each mutator flush remembered sets.
abstract void	resumeAllMutators() Resume all mutators blocked for GC.
abstract void	spawnCollectorContext(CollectorContext context) Spawns a thread to execute the supplied collector context.
abstract void	stopAllMutators() Stop all mutator threads.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

UNKNOWN_GC_TRIGGER

public static final int UNKNOWN_GC_TRIGGER

An unknown GC trigger reason. Signals a logic bug.

See Also:

Constant Field Values

INTERNAL_PHASE_GC_TRIGGER

public static final int INTERNAL_PHASE_GC_TRIGGER

Concurrent collection phase trigger.

See Also:

Constant Field Values

EXTERNAL_GC_TRIGGER

public static final int EXTERNAL_GC_TRIGGER

Externally triggered garbage collection (eg call to System.gc())

See Also:

Constant Field Values

RESOURCE_GC_TRIGGER

public static final int RESOURCE_GC_TRIGGER

Resource triggered garbage collection. For example, an allocation request would take the number of pages in use beyond the number available.

See Also:

Constant Field Values

INTERNAL_GC_TRIGGER

public static final int INTERNAL_GC_TRIGGER

Internally triggered garbage collection. For example, the memory manager attempting another collection after the first failed to free space.

See Also:

Constant Field Values

TRIGGER_REASONS

public static final int TRIGGER_REASONS

The number of garbage collection trigger reasons.

See Also:

Constant Field Values

triggerReasons

protected static final String[] triggerReasons

Short descriptions of the garbage collection trigger reasons.

Constructor Detail

Collection

public Collection()

Method Detail

spawnCollectorContext

public abstract void spawnCollectorContext(CollectorContext context)

Spawns a thread to execute the supplied collector context.

Parameters:

context - the context to execute

getDefaultThreads

public abstract int getDefaultThreads()

Returns:

The default number of collector threads to use.

getActiveThreads

public abstract int getActiveThreads()

Returns:

The number of active threads.

blockForGC

public abstract void blockForGC()

Block for the garbage collector.

prepareMutator

public abstract void prepareMutator(MutatorContext m)

Prepare a mutator for collection.

Parameters:

m - the mutator to prepare

requestMutatorFlush

public abstract void requestMutatorFlush()

Request each mutator flush remembered sets. This method will trigger the flush and then yield until all processors have flushed.

stopAllMutators

public abstract void stopAllMutators()

Stop all mutator threads. This is current intended to be run by a single thread.

Fixpoint until there are no threads that we haven't blocked. Fixpoint is needed to catch the (unlikely) case that a thread spawns another thread while we are waiting.

resumeAllMutators

public abstract void resumeAllMutators()

Resume all mutators blocked for GC.

outOfMemory

public abstract void outOfMemory()

Fail with an out of memory error.